Seventy years ago this month Nato was established to protect western Europe and the freedoms of its inhabitants from the threat of Soviet communism. It has become clear to me that we now need a similar organisation to protect western intellectuals from a growing threat to academic freedom.

The North Atlantic Treaty, signed by 12 governments in Washington on April 4, 1949, was a treaty of mutual defence “to safeguard the freedom, common heritage and civilisation of their peoples, founded on the principles of democracy, individual liberty and the rule of law”. Article 5 of the treaty states that “an armed attack against one or more of [the signatories] . . . shall be considered an attack against them all”.